tecciztli (Mdz67r)

A sign next to a tecciztli at the Templo Mayor refers to the shell as a "turbinella angulata" and a large "gastropod shell...from the Atlantic coast of Mexico." It continues, "The presence of several specimens of the periostracum, a protein layer that covers the shell's surface, attests to the fact they were collected alive by divers, because this layer is lost when the animal dies in the sea and is dragged onto the beach by the swell of waves. A specimen of this species was found covered with blue pigment, perhaps to emphasize its relationship with water, in one of the offerings dedicated to Tlaloc. It also served for the production of a large number of objects including the ehecacozcatl, the pectoral characteristic of the god Ehecatl-Quetzalcoatl, which is produced by transversally cutting the shell's spiral whorls. Beads and pendants made of this shell have also been found."